The reading of neighbor cell system information by a mobile station in a wireless communication network is beneficial in many situations. One such situation arises in 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) networks in the presence of Home eNBs (HeNBs), which are also referred to as femto cells. An LTE HeNB is a low power eNB that provides coverage in hotspots, e.g., in homes, etc., to a small number of users. A physical cell identifier (PCID) uniquely identifies each macro cell, since the network is planned and deployed such that macro cells with the same PCID are separated by a very large distance to facilitate re-use of PCIDs. In contrast, HeNBs are deployed by users in an uncoordinated fashion with no PCID planning. As a result it is possible to have two HeNBs under the coverage of a macro cell that use the same PCID, which may result in PCID confusion.
For handover, the network needs to know precisely to which cell to handover a mobile station. One approach to resolve PCID confusion is for the mobile station to read the unique cell identifier (cell global ID or CGI) or CSG ID in System Information block 1 of the target HeNB and to report the CGI or the CSG ID. However, mobile stations in connected mode in LTE Rel-8 are not required to acquire system information messages from neighboring cells. Reading neighbor cell system information can cause significant interruptions to an ongoing connection with a serving cell. This interruption is particularly problematic when there is an ongoing voice call. Thus it is desirable to reduce loss of data packets (e.g., voice frames) transmitted between a mobile station and a serving cell when the mobile station attempts to acquire neighbor cell system information.
The various aspects, features and advantages of the disclosure will become more fully apparent to those having ordinary skill in the art upon careful consideration of the following Detailed Description thereof with the accompanying drawings described below. The drawings may have been simplified for clarity and are not necessarily drawn to scale.